Compressor

ABSTRACT

A compressor, capable of reducing friction among a vane and parts which perform relative motion with the vane in driving the compressor by using materials having thermal expansion coefficient of the vane as same as or higher than 2.5×10 −5 /° C., reducing consumption of activation energy and friction loss by gaining lower friction coefficient and higher abrasion resistance, reducing abrasion of the parts, controlling heat transfer, and increasing suction amount of refrigerant gas, can improve compression performance.

TECHNICAL FIELD

[0001] The present invention relates to a compressor and particularly,to a vane of a compressor and mounting structure thereof, capable ofminimizing friction loss and generation of frictional heat caused byrelative motion in operating a compressor.

BACKGROUND ART

[0002] Generally, a compressor is an instrument for compressing gas suchas refrigerant and the like. The compressor generally includes anelectric mechanism unit for generating a driving force and a compressionunit for compressing gas by receiving the driving force of the aboveelectric mechanism unit and is classified into a rotary compressor, areciprocating compressor and a scroll compressor according to thecompression mechanism of the compression unit.

[0003]FIGS. 1 and 2 show an embodiment of the compressor, as showntherein, a rotational shaft 30 coupled with a rotor 21 of a drivingmotor 20 rotates when the driving motor 20 mounted in the hermeticcontainer 10 is driven and according to rotation of the rotational shaft30, an eccentric portion 31 provided on the rotational shaft 30eccentrically rotates in a compression space (P) of a cylinder 40positioned at the lower side of the driving motor 20.

[0004] As the eccentric portion 31 of the rotational shaft 30eccentrically rotates in the compression space (P) of the cylinder 40, arolling piston 50 which is coupled with the eccentric portion 31 islinearly contacted on an inner wall of the compression space (P) of thecylinder 40 and performs a circular movement in the compression space(P) of the cylinder 40 under the condition that it is linearly contactedon the vane which is coupled with a vane slot 41 formed in the cylinder40.

[0005] As the rolling piston 50 performs a circular movement in thecompression space (P) of the cylinder 40, as the compression space (P)of the cylinder 40 divided by a vane 60 is converted into a suctionregion (a) and a compression region (b), refrigerant gas is suckedthrough a suction port 42 provided on the cylinder 40, compressed anddischarged through a discharge port 43 provided on the cylinder 40. Thecompressed refrigerant gas discharged through the discharge port 43 isdischarged into the hermetic container 10 through a discharge throughhole 71 formed in an upper bearing plate 70 among the upper bearingplate 70 and lower bearing plate 80 which are respectively covered andcoupled at both sides of the cylinder 40, and refrigerant gas dischargedinto the hermetic container 10 of high temperature and pressure isdischarged through a discharge pipe 11 which is coupled with the upperportion of the hermetic container 10.

[0006] At this time, as the compression space (P) of the cylinder 40 isdivided into a suction region (a) and a compression region (b), anopen/close means 90 coupled with the upper portion of the upper bearingplate 70 is operated together and the discharge through hole 71 isopened or closed.

[0007] Reference numeral 12 which is not described above designates asuction pipe, reference numeral 13 designates a combining bolt, 22designates a stator and 91 designates a muffler.

[0008] On the other hand, the vane 60 which is inserted in the vane slot41 of the cylinder 40 and is linearly contacted on the rolling piston 50is, as shown in FIG. 3, formed by forming a contact curved surfaceportion 61 having a predetermined curvature on a side surface of thevane body having predetermined thickness and area.

[0009] The vane 60 is manufactured by processing a whole surface of ahigh-speed steel of a certain shape by lathe turning method.

[0010] The vane 60 is inserted in the vane slot of the cylinder 40 sothat the contact curved surface portion 61 is contacted on the, rollingpiston 50, and the other side of the contact curved surface portion 61of the vane 60 is elastically supported by a spring S and coupled withthe rolling piston 50 to be contacted.

[0011] However, in the above structure, as the rotational shaft 30rotates in the operation, the vane 60 is linearly contacted on therolling piston 50 and performs relative movement. The vane 60 has severefriction with the rolling piston 50 and the inner wall of the vane slot41 as it divides the compression space (P) of the cylinder 40 into thesuction region (a) and the compression region (b) performing linearreciprocating movement along the vane slot 41. Also, as the frictionheat by the friction is generated, a relatively large input energy isrequired.

[0012] Particularly, in the initial state of activation, since supply oflubricating oil can not be smoothly done, large activation energy isneeded by static friction coefficient and it is difficult to select aproper motor.

[0013] Also, friction heat by friction of the vane 60, and inner wall ofthe rolling piston 50 and vane slot 41 is transmitted to the cylinder40, thus to heat the suction region (a) of the cylinder 40 and degradecompression efficiency of the refrigerant gas.

[0014] Particularly, the vane 60 is formed with high-speed steel havinga relatively small thermal expansion coefficient and therefore, gascompression efficiency was further degraded since heating valuegenerated in case of friction among the vane 60 formed with steel, andinner wall of the rolling piston 50 and vane slot 41.

DISCLOSURE OF THE INVENTION

[0015] Therefore, it is an object of the present invention to provide acompressor, capable of minimizing friction loss and generation offrictional heat caused by relative motion in operating a compressor.

[0016] To achieve these objects, there is provided a compressor,comprising: a cylinder assembly having a compression space; a rotationbody which is inserted in the compression space of the cylinder assemblyso that it can rotate; and a vane which is inserted in a vane slotformed in the cylinder assembly to be contacted on the rotation body,for dividing the compression space of the cylinder assembly into asuction region and a compression region performing relative motionaccording to rotation of the rotation body, wherein the vane of acompressor is formed with materials having a thermal expansioncoefficient as same as or larger than 2.5×10⁻⁵/° C.

BRIEF DESCRIPTION OF THE DRAWINGS

[0017]FIG. 1 is a longitudinal sectional view showing a conventionalcompressor;

[0018]FIG. 2 is a plane sectional view showing the conventionalcompressor;

[0019]FIG. 3 is a perspective view showing a vane of FIG. 1;

[0020]FIG. 4 is a longitudinal sectional view showing a compression unitof a compressor in accordance with the present invention;

[0021]FIG. 5 is a plane sectional view showing the compression unit ofthe compressor of FIG. 4;

[0022]FIG. 6 is a perspective view showing a vane used in the compressorof the present invention;

[0023]FIG. 7 is a partial sectional view illustrating an operationalstate of the compressor of the present invention;

[0024]FIG. 8 is a longitudinal sectional view showing the compressionunit of the compressor in case that the compressor of the presentinvention are applied to another compressor;

[0025]FIG. 9 is a plane sectional view showing the compression unit ofthe compressor in case that the compressor of the present invention areapplied to another compressor; and

[0026]FIG. 10 is a partial perspective view showing the compression unitof the compressor shown in FIG. 8 in section.

MODES FOR CARRYING OUT THE PREFERRED EMBODIMENTS

[0027] Hereinafter, the compressor of the present invention will bedescribed with reference to the embodiments shown in the accompanieddrawings.

[0028]FIGS. 4 and 5 show embodiments of a compression unit of acompressor to which a vane of a compressor of the present invention areapplied. As shown in the drawings, firstly, the compression unit of thecompressor includes a cylinder assembly (K) having a compression space(P) therein, a rotational shaft 30 which penetrates and is inserted inthe cylinder assembly (K) so that an eccentric portion 31 is provided onthe compression space (P) of the cylinder assembly (K) by having theeccentric portion 31, and a rolling piston 50 which is inserted to theoutside of the rotational shaft 30 and provided on the compression space(P) of the cylinder assembly (K).

[0029] The rotational shaft 30 is connected with an electric mechanismunit for generating a driving force and the rolling piston 50 and theeccentric portion 31 for a rotation body.

[0030] The cylinder assembly (K) includes a cylinder 40 in which athrough hole is formed, an upper bearing plate 70 and lower bearingplate 80 for respectively supporting the rotational shaft 30 beingcovered-coupled with the both sides of the cylinder 40 to seal thethrough hole of the cylinder 40.

[0031] The compression space (P) is formed by the upper and lowerbearing plates 70 and 80 which are covered and coupled with the throughhole of the cylinder 40 both sides of the cylinder 40.

[0032] A suction port 42 which is penetrated at a side of the cylinder40 is formed at a side of the cylinder 40, a discharge port 43 is formedat a side of the suction port 42, and a vane slot 41 which is penetratedto have a predetermined width between the suction port 42 and dischargeport 43 is formed.

[0033] In addition, a discharge hole 71 penetrated and formed to beconnected with the discharge port 43 of the cylinder 40 is formed in theupper bearing plate 70.

[0034] A vane 100 having a predetermined shape is inserted so that itcan perform a linear movement in the vane slot 41 of the cylinderassembly (K), and the vane 100 is elastically supported by the spring S.Accordingly, a side of the vane 100 is linearly contacted on thecircumferential surface of the rolling piston 50 provided on thecompression space (P) of the cylinder assembly (K).

[0035] The rolling piston 50 is linearly contacted on the inner wall ofthe compression space (P) of the cylinder assembly (K), and the vane 100is linearly contacted on the circumferential surface of the rollingpiston 50, thus to divide the compression space (P).

[0036] As shown in FIG. 6, in the vane 100, a contact curved surfaceportion 102 is formed with curved surfaces, having a predeterminedcurvature in a side surface of the vane body 101 which has predeterminedthickness and area, and is contacted on the circumferential surface ofthe rolling piston 50.

[0037] The vane 100 is made of materials having a thermal expansioncoefficient higher than 2.5×10⁻⁵/° C. and it is desirable that the vane100 is made of materials having a thermal expansion coefficient between3.5×10⁻⁵/° C. and 5.0×10⁻⁵/° C.

[0038] On the other hand, the vane 100 is made of high polymer compositematerials having a large thermal expansion coefficient and a small heattransfer coefficient, and it is desirable that it is made of polymer orpolyamide as the high polymer composite materials.

[0039] Particularly, the polyamide has identical characteristics to thesteel in terms of chemical resistance against refrigerant gas and hassmaller friction coefficient and larger abrasion resistance.

[0040] In addition, the vane slot 41 in which the vane 100 made ofmaterials having thermal expansion coefficient higher than 2.5×10⁻⁵/° C.is inserted is formed to have relatively larger assembly clearance withthe vane 100.

[0041] That is, the vane slot 41 is in which the vane 60 formed withmaterials having a large thermal expansion coefficient is inserted andthe vane 60 are formed to have a small assembly clearance inconsideration of the thermal expansion coefficient (1.1×10⁻⁵/° C.) ofthe vane 60 formed with steel, but the vane slot 41 in which the vane100 formed with materials having a high thermal expansion coefficient isinserted and vane 100 are formed to have a relatively large assemblyclearance. Therefore, the assembly clearance among the vane 100 and vaneslot 41 under the condition that the compressor is not driven ismaintained large.

[0042] An open/close means 90 for opening and closing the discharginghole 71 is mounted in the upper bearing plate 70 of the cylinderassembly (K).

[0043] Reference numeral 10 which is not described designates a hermeticcontainer, 12 designates a suction pipe, 13 designates a combining boltand 91 designates a muffler.

[0044] The operation effect of the vane of the compressor in accordancewith the present invention will be described as follows.

[0045] Firstly, the compression unit of the compressor revolves on thebasis of the center of the shaft in the compression space (P) of thecylinder assembly (K) under the condition that the rolling piston 50coupled with the eccentric portion 31 of the rotational shaft 30 byrotation of the rotational shaft 30 is contacted on the vane 100 whenthe rotational shaft 30 rotates by receiving a rotary force of theelectric mechanism unit.

[0046] As the rolling piston 50 revolves and rotates, the volume of thecompression space (P) of the cylinder assembly (K) is changed togetherwith the linear reciprocating movement of the vane 100. That is, as thecompression space (P) is converted into the suction region (a) and thecompression region (b), refrigerant gas of low temperature and pressureis sucked to the compression space (P) of the cylinder assembly (K)through the suction pipe 12 and suction port 42, compressed anddischarged through the discharge port 43 and discharge hole 71.

[0047] In the above process, the vane 100 receives a lateral pressure bypressure difference of the suction region (a) and the compression region(b) of the compression space (P) of the cylinder assembly (K) andperforms linear reciprocating movement. The contact curved surfaceportion 102 of the vane is contacted on the circumferential surface ofthe rolling piston 50 being elastically supported on the circumferentialsurface.

[0048] At this time, the assembly clearance of the vane 100 and vaneslot 41 in initially driving the compressor is maintained large and asshown in FIG. 7, the vane 100 is heated and expanded by heat generatedin driving the compressor normally after the initial driving.Accordingly, the interval between the vane 100 and the vane slot 41 ismaintained finely.

[0049] Therefore, due to the large interval between the vane 100 and thevane slot 41 in initially driving the compressor, little frictionbetween the vane 100 and inner wall of the vane slot 41 is generated andaccordingly little activation energy is consumed. Also, the intervalbetween the vane 100 and vane slot 41 becomes shorter by expansion ofthe vane 100 in driving the compressor normally, thus to minimizeleakage of gas.

[0050] Particularly, little friction is generated under the conditionthat sufficient oil is not supplied in initially driving, thus tosubstantially reduce waste of activation energy.

[0051] In addition, when the vane 100 is made of polymer or polyamidematerials, heat transfer toward the suction region (a) of thecompression space (P) of the cylinder assembly (K) is minimized sinceheating value is relatively small and heat transfer coefficient issmall, when the friction is generated. Therefore, an amount of thesucked refrigerant gas is increased, thus to increase compressioncoefficient.

[0052] Also, the vane 100 formed with polymer or polyamide materialsgains lower friction coefficient and larger friction resistance andlengthens life span of the vane 100.

[0053] Hereinafter, another compressor to which the vane of thecompressor in accordance with the present invention are applied will bedescribed with reference to FIGS. 8, 9 and 10.

[0054] As shown in FIGS. 8, 9 and 10, the compression unit of anothercompressor has a compression space (P) therein and a rotational shaft110 is inserted penetrating the center of the compression space (P) ofthe cylinder assembly (K) in which the suction flow path f1 anddischarge flow path f2 which are respectively connected to thecompression space (P). The rotational shaft 110 is coupled with theelectric mechanism unit for generating a driving force.

[0055] The cylinder assembly (K) includes a cylinder 120 in which athrough hole in the circular shape is formed, an upper bearing plate 130and a lower bearing plate 140 which are covered and coupled on theupper/lower surfaces of the cylinder 120, for forming the compressionspace (P) together with the cylinder 120 and supporting the rotationalshaft 110.

[0056] At a side of the upper bearing plate 130 and the lower bearingplate 140, vane slots 131 and 141 which are penetrated and formed tohave predetermined width and length are respectively formed.

[0057] The rotational shaft 110 includes a shaft portion 111 formed tohave predetermined outer diameter and length and a dividing plate 150which is lengthened and formed to have predetermined thickness and areaat a side of the shaft portion 111, for dividing the compression space(P) of the cylinder assembly (K) into first and second spaces 121 and122.

[0058] The dividing plate 150 of the rotational shaft 110 includes anupper convex curved surface portion r1 which is formed in a circularshape having a predetermined thickness and has a convex curved surface,a lower concave curved surface portion r2 having a concave curvedsurface, and a connection curved surface portion r3 for connecting theupper convex curved surface portion r1 and lower concave curved surfaceportion r2 in case of shown from the side and formed in a wave curvedsurface shape of a sine wave.

[0059] Also, vanes 100′ are respectively inserted in the vane slot 131of the upper bearing plate 130 and vane slot 141 of the lower bearingplate 140, and elastic supporting means 160 for elastically supportingthe vanes 100′ are coupled with the upper bearing plate 130 and lowerbearing plate 140. Accordingly, the vane 100′ is abutted being linearlycontacted on the dividing plate 150 by the elastic supporting means 160.

[0060] In the vane 100′, a contact curved surface portion 104 in therounding shape being abutted on the wave curved surface of the dividingplate 150 is formed, and an outer curved surface portion 105 contactedon the inner wall of the compression space (P) of the cylinder assembly(K) and an inner curved surface portion 106 which is contacted on thecircumferential surface of the rotational shaft 110 are formed on bothsurfaces of the vane body 103. The vane slots 131 and 141 in which thevane 100′ is inserted is formed in a square shape corresponding to thecross-sectional shape of the-vane 100′.

[0061] The vane 100′ is made of materials having thermal expansioncoefficient as same as or higher than 2.5×10⁻⁵/° C. and it is desirablethat the vane 100′ is made of materials having thermal expansioncoefficient between 3.5×10⁻⁵/° C. and 5.0×10⁻⁵/° C.

[0062] On the other hand, the vane 100′ is made of high polymercomposite materials having a large thermal expansion coefficient andsmall heat transfer coefficient, and it is desirable that it is made ofpolymer or polyamide as the composite materials.

[0063] Particularly, the polyamide has an identical characteristic asthe steel in terms of chemical resistance against the refrigerant, andit has smaller friction coefficient and larger friction resistance thanthe vane which is formed with the steel.

[0064] That is, the vane slot 41 is in which the vane 60 formed withmaterials having a large thermal expansion coefficient is inserted andvane 60 are formed to have a small assembly clearance in considerationof the thermal expansion coefficient (1.1×10⁻⁵/° C.) of the vane 60formed with steel, but the vane slots 131, 141 in which the vane 100′formed with materials having a large thermal expansion coefficient isinserted and vane 100′ are formed to have a relatively large assemblyclearance. Therefore, the assembly clearance among the vane 100′ andvane slots 131 and 141 under the condition that the compressor is notdriven is maintained large.

[0065] In addition, an open/close means 170 for opening or closing thedischarge flow path f2 is mounted on a side surface of the respectivebearing plates 130 and 140 of the cylinder assembly (K).

[0066] Reference numeral 10 which is not described designates a hermeticcontainer and 180 designates a muffler.

[0067] The operation effect of the compression unit of the abovecompressor to which the vane of the compressor in accordance with thepresent invention are applied will be described as follows.

[0068] Firstly, in the compression unit of the compressor, the dividingplate 1 50 of the rotational shaft 110 rotates in the compression space(P) of the cylinder assembly (K) when the rotational shaft 110 rotatesby receiving a rotary force of the driving force of the electricmechanism unit.

[0069] As the dividing plate 150 of the rotational shaft 110 rotates inthe compression space (P) of the cylinder assembly (K), vanes 100′ whichare connected with the dividing plate 150 are moved together, a firstand second spaces 121 and 122 of the compression space (P) divided bythe dividing plate 150 are converted into the suction regions 121 a and122 a and compression regions 121 b and 122 b. Then, refrigerant gas issucked to first and second spaces 121 and 122 together with theoperation of the open/close means 170, and such process is repeated.

[0070] As the dividing plate 150 of the rotational shaft 110 rotates inthe compression space (P) of the cylinder assembly (K), under thecondition that the vane 100′ which is positioned vertically and radiallyto the dividing plate 150 is elastically supported by the elasticsupporting means 160, and the vane 100′ performs linear reciprocatingmovement upwards and downwards along the wave curved surface of thedividing plate 150.

[0071] In the above process, the vanes 100′ performs linearreciprocating movement receiving pressure to the lateral direction bypressure difference of the suction regions 121 a and 122 a andcompression regions 121 b and 122 b of the compression space (P) of thecylinder assembly (K), and the contact curved surface portion 104 of thevane 100′ is elastically supported on the outer curved surface of thedividing plate 150 an contacted by the elastic supporting means 160.

[0072] At this time, in case of initially driving the compressor, theassembly clearance of the vane 100′ and vane slots 131 and 141 ismaintained large and the vane 100′ is heated and expanded by heatgenerated in driving the compressor normally after the initial driving.Accordingly, the interval between the vane 100′ and the vane slots 131and 141 can be maintained finely.

[0073] Therefore, as the clearance of the vane 100′ and vane slots 131and 141 increases, little friction among the vane 100′ and inner wall ofthe vane slots 131 and 141 is occurred and little activation energy isconsumed. Also, in case of driving the compressor normally, theclearance between the vane 100′ and vane slots 131 and 141 decreases byexpansion of the vane 100′, thus to minimize leakage of refrigerant gas.Particularly, little friction is generated under the condition that oilis not sufficiently supplied and consumption of activation energy issubstantially reduced.

[0074] In addition, in case the vane 100′ is formed with polymer orpolyamide materials, heating value is relatively small in case offriction and heat transfer coefficient decreases. Accordingly, heattransfer to the suction regions 121 a and 122 a of the compression space(P) of the cylinder assembly (K) is minimized and amount of the suckedrefrigerant gas is increased, thus to improve compression efficiency.Also, the vane 100′ formed with polymer or polyamide materials becomesto have a small friction coefficient and large abrasion resistance, thusto lengthen life span of the vane 100′.

[0075] As described above, the vane of the compressor can reducefriction the vane and parts which perform relative motion with the vane,reduce consumption of activation energy and friction loss, reduceabrasion of the parts and control heat transfer, thus to increasesuction amount of the refrigerant gas and improve compressionperformance.

[0076] At the present invention may be embodied in several forms withoutdeparting from the spirit or essential characteristics thereof, ifshould also be understood that the above-described embodiments are notlimited by any of the details of the foregoing description, unlessotherwise specified, but rather should be constructed broadly within itsspirit and scope as defined in the appended claims, and therefore allchanges and modifications that fall within the meets and bounds of theclaims, or equivalence of such meets and bounds are therefore intendedto be embraced by appended claims.

1. A compressor, comprising: a cylinder assembly having a compressionspace; a rotation body which is inserted in the compression space of thecylinder assembly so that it can rotate; and a vane which is inserted ina vane slot formed in the cylinder assembly to be contacted on therotation body, for dividing the compression space of the cylinderassembly into a suction region and a compression region performingrelative motion according to rotation of the rotation body, wherein thevane of a compressor is formed with materials having a thermal expansioncoefficient as same as or larger than 2.5×10⁻⁵/° C.
 2. The compressor ofclaim 1, wherein the vane is made of a material having a thermalexpansion coefficient between 3.5×10⁻⁵/° C. and 5.0×10⁻⁵/° C.
 3. Thecompressor of claim 1, wherein the vane is made of polymer compositematerials.
 4. The compressor of claim 1, wherein the vane is made ofpolyamide.
 5. The compressor of claim 1, wherein the assembly clearancebetween the vane and slot is set larger than an optimal assemblyclearance in consideration of thermal expansion under the condition ofnormal driving.